2008-11-24_PERMIT FILE - C1996083 (12)

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Geotechnical Data Report Bruce Park Dam Bowie Resources, Limited April 2001 } System (USCS). These materials are described as stiff, moist, and dark brown in color. The measured in-place dry densities of the Old Embankment materials ranged from 92 pcf to 99 pcf. These in-place densities are 88 to 95 percent of the maximum Proctor dry density. The measured in-place natural moisture contents ranged from 21.9 to 29.8 percent. The in-place moisture contents of the Old Embankment materials are 2.0 to 9.8 percent above the optimum Proctor moisture content. The laboratory testing results also indicate these materials are normally consolidated and have very low permeability. 7.1.3 Foundation Soils Foundation soils below the main embankment were encountered in Borings BD-103 and BD-105. These materials are apparently associated with an older glacial till deposit, the Lands End Formation. The foundation soils are generally sandy low to high plasticity clays. They are visually classified as CL and CH materials according to USCS. These materials are described as very stiff to hard, moist, and yellow- brown to brown in color. They contain 20 to 35 percent sand and gravel particles up - l to 3-inches is size with occasional cobbles up to 12-inches in size. The particles are composed of igneous and metamorphic rock. The measured in-place dry densities of the foundation soils ranged from 99 pcf to 105 pcf. The laboratory testing results also indicate these materials are slightly to highly over-consolidated. 7.9.4 Bedrock Foundation bedrock below the main embankment was encountered in Borings BD- 101, BD-102, BD-103 and BD-105. The bedrock consists of sandstone, siltstone, and claystone of the Mesa Verde Group. The bedrock encountered in Boring BD-101, below the left abutment of the Main Dam, consists of siltstone and sandstone to the total depth explored of 20 feet. The bedrock is described as hard, dry, gray-brown siltstone that grades to fine grained sandstone. The bedrock encountered in Boring BD-102, below the right abutment of the plain Dam generally consists of interbedded siltstone, silty claystone, and silty sandstone. The interbedded siltstone and silty claystone are described as moderately soft to soft, gray to yellow, slightly to moderately weathered, very thinly bedded with nearly horizontal bedding planes. Jointing generally parallels the bedding with some near GEI Consultants, Inc. 17 99292'1-34-16GeotechnicalData Report